(Adds detail on timeline views and user growth, updates share price)
SAN FRANCISCO, Feb 5 (Reuters) - Twitter Inc reported its slowest pace of user growth during the fourth quarter, dashing hopes the social media phenomenon can sustain its torrid pace of expansion and wiping out more than 10 percent of its value on Wednesday.
The company posted better-than expected quarterly revenue of $243 million in its first results as a public company. But investors focused on the anemic user growth, as well as a severe decline in timeline views, a measure of user engagement.
Timeline views dropped sharply from 159 billion to 148 billion in the quarter, signaling that users were refreshing their Twitter accounts less often.
Twitter, which held a highly-anticipated initial public offering in November at $26 a share, has divided investor opinion in the months since, as shares more than doubled to more than $66 despite an absence of news.
User growth, a closely watched metric, sputtered. It averaged 241 million monthly users in the December quarter, up just 3.8 percent from the previous three months - the lowest rate of quarter-on-quarter since Twitter began disclosing user figures.
Twitter's user numbers grew at 10 percent, 7 percent, and 6 percent during the first three quarters of the year, respectively.
But the efficacy of its advertising business model - which places ads inside users' timelines every time they refresh - appeared to steadily improve. The company said it made $1.49 per one thousand timeline views, a significant jump of 76 percent from a year prior. (Reporting by Gerry Shih; Editing by Nick Zieminski)